The invention relates to a miniature circuit breaker with a latch.
A miniature circuit breaker with a latch is known per se. The latch comprises a toggle lever gear which has a link which is in each case connected in an articulated manner with a switching handle and a coupling element; the coupling element connects the link with the contact lever also in an articulated manner. In the switched-on state, the gear is in a first stable position from which the gear can be brought into a second stable position via a dead-center position by means of a tripping mechanism; in this second position, the contact lever is rotated in the switched-off direction and the contact point is permanently opened. The tripping mechanism used could be an electromagnetic or thermal trip, the latter in the form of a thermal bimetallic strip or a strip of a shape-memory alloy.
So that the toggle lever gear can be moved from its first stable position to its second stable position, a specific force is applied which essentially depends on the force with which the coupling element acts on the contact lever.